While the reduction of operational carbon becomes more difficult after a building has been built, designing for energy efficiency can improve building performance. Very rarely can mechanical systems be completely omitted from architecture. In these cases, selecting efficient MEP systems (e.g. centralized vs. decentralized heating/cooling, heat/energy recovery ventilation) will make a significant difference in operational carbon output. We can also drastically improve building performance without over-reliance on mechanical systems through passive thermal strategies:
1. NATURAL VENTILATION
Natural ventilation is the flow of fresh air inside of the building because of pressure differences caused by buoyancy and wind. The types of natural ventilation can be grouped in direct ventilation (though façade openings), cross ventilation (between openings in two or more facades) and stack ventilation (driven by the rise of the warm air).
2. PASSIVE HEATING AND COOLING
By analyzing the sun’s angle and understanding how it changes throughout the year, we can design architecture that is heated and cooled at the right times.
3. IMPROVE INSULATION
Use continuous insulation to increase the efficiency of the building envelope and eliminate thermal bridging.
4. PASSIVE DAYLIGHTING
Decrease the need for artificial lighting which will reduce the overall energy consumption of the building.
5. IMPROVE AIRTIGHTNESS
Reduce heat transfer by eliminating its favorite method of movement, convection. This starts at openings such as doors and windows but can also be achieved by creating a continuous air barrier at the entire envelope using smart barriers and efficient detailing.
Stay tuned for next week’s topic: Embodied Carbon Hot Spots.
